Drill string >> Wall Thickness Inpection

Precision Inspection

Our machining at very high precision levels requires not only good equipment,but also skilled people and effective organizing.We focus on precision all the time,and precision inspections are performed during every production process.While inspecting the threads,working gages of different sizes which have been sent to China Master Gage Centre for inspection half a year are employed and paid great attention to.

Inspectors hold valid inspection certificate issused by the authority of China Metrology Institute and they have been nominated by our company.

Non-Destructive Examination

All materials in Shenlong’s facility have been examined for both surface and internal defects.

Ultrasonic Tests are utilized through the entire process. Material coming into factory, after heat-treated (or forging), finished products, there are at least 3 times of Ultrasonic Tests for each products.

Magnetic Particle Examination has been performed to detect surface defects and thread defects.

Employees who perform NDE have valid Level II certificate.

Mechanical Properties Test

Shenlong performs Tensile Test, Impact Test and Hardness Test in Shenlong’s own laboratory. To ensure the quality, test samples are taken from both ends of each bar of Drill Collars.

Tensile and Impact test are performed according to API SPEC 7-1.

Hardness can be assured both 1” beneath the outer surface according to API SPEC 7-1 and the 4 quadrants across the neck OD according to NS-1.